Synaptic dysfunction is the best anatomical correlate of early cognitive impairment in Alzheimer's disease (AD). Electroencephalography (EEG) directly reflects brain electrical activity at the level of synapses. The aim of the present study was to investigate correlations of quantitative EEG measures, global field power (GFP) and global field synchronization (GFS), with conventional cerebrospinal fluid (CSF) biomarkers of neurodegeneration in patients diagnosed with subjective cognitive decline (n = 210), mild cognitive impairment (n = 230), and AD (n = 197). Decreased CSF amyloid β42 significantly correlated with increased theta and delta GFP, whereas increased p- and t-tau with decreased alpha and beta GFP. Decreased CSF amyloid β42 and increased p- and t-tau were significantly associated with decreased GFS alpha and beta. Subanalysis of the separate diagnostic groups demonstrated significant correlations between CSF biomarkers and generalized power and synchronization already in the subjective cognitive decline and mild cognitive impairment group. These results provide evidence that quantitative EEG measures are associated and possibly sensitive to distinct AD-like CSF biomarker profiles in cognitively impaired patients and are therefore promising early noninvasive markers of AD.

Impaired immune responses in cancer patients have been associated with oxidative stress. Increased levels of reactive oxygen species released from activated, tumor-infiltrating macrophages or granulocytes may therefore constitute a hurdle for effective immunotherapy against cancer. In this study, we investigated functional consequences and molecular events in T cells exposed to low levels of oxidative stress. We observed that cytokine production of human PBMC, upon stimulation with an HLA-A*0201-restricted influenza peptide and nonspecific receptor cross-linking, was reduced after exposure to micromolar levels of H2O2. Functional impairment as measured by IFN-γ release occurred earlier and at lower doses of exogenously added H2O2 than required to induce apoptosis. This suggests that there is a dose window of oxidative stress leading to T cell unresponsiveness in the absence of apoptosis. The reduction of Th1 cytokines, induced by H2O2, was predominantly observed in memory/effector (CD45RO+) T cells and correlated with a block in NF-κB activation. IL-10 production was more profoundly influenced by low doses of H2O2 than IFN-γ, TNF-α, and IL-2. The influence of H2O2 on production of IL-10 was not significantly different between memory/activated and naive T cells. These observations suggest that Th1 and Th2 cytokines are differently regulated under conditions of oxidative stress. Taken together, these findings may explain why Ag-experienced, CD45RO+, T cells found in the tumor milieu are functionally suppressed.

We have studied a large Swedish family with a mutation in the nerve growth factor beta (NGFB) gene causing insensitivity to deep pain without anhidrosis (hereditary sensory and autonomic neuropathy, type V; HSAN V). Painfree joint destruction and fractures were common. Peripheral nerve conduction was normal, but temperature thresholds were increased. Sural nerve biopsies showed a moderate loss of A delta fibers and a severe reduction of C fibers. The three most severely affected cases were all born to consanguineous parents, and were homozygotes for the causal genetic mutation. Treatment of these patients is discussed.

Althoff, Andersson, and Andersson Reply: The elastic scattering of slow heavy gas-phase particles from solid surfaces exhibits some strikingly simple behavior according to a semiclassical description of the Debye-Waller factor e 22W . The model predicts that the Debye-Waller exponent 2W and hence the probability for elastic scattering is independent of the particle mass m at low surface temperature [1] and 2W~m 1͞2 T [1,2] at elevated temperatures. We found from our experiments [3] involving low-energy nozzle beams of Ne, Ar, and Kr scattered from a Cu(111) surface, that the measured elastic scattering behavior of the slow inert gas-phase particles in consistent with the predicted mass dependencies.Siber and Gumhalter argue that neither of the semiclassical mass dependencies holds and that the experiments can be interpreted only by quantum theory. Concerning the dependence on m 1͞2 at elevated temperatures we show here that their quantum calculations on the contrary agree very well with the simple semiclassical prediction. This observation is visualized in Fig. 1 which displays a relative comparison of the quantum and semiclassical decay parameters b q and b sc ͑2W bT ͒ at elevated temperatures, obtained from the slopes of the ln I 00 versus T plots in Fig. 1 of Ref.[4]. The two models exhibit a similar falloff of ln I 00 with T , which results in a ratio b q ͞b sc close to 1 for Ne, Ar, and Kr. This clearly demonstrates that the two models to a very good approximation give the same mass dependence, i.e., m 1͞2 .The quantum values of 2W at T 0 in Fig. 2 of Ref.[4] ͑2W q ͒ are about (70-80)% of the semiclassical ones at the m values for Ne, Ar, and Kr and agree very well with the measured low temperature data ͑2W e ͒ for Ar and Kr, W e ͞W q ഠ 1.1 for both particles. The quantum correction increases significantly with decreasing particle mass. We may obtain an independent test of the accuracy of this prediction with use of a suitable light test particle like H 2 . The H 2 -Cu͑111͒ interaction potential has a well depth of 29.5 meV and falls in the range between Ne and Ar [3]. Interpolating in the data of Ref.[4] we obtain at m 2 a quantum value 0.16, which is less than 25% of the corresponding semiclassical value 0.72. We can relate this prediction to our measurements for H 2 [5] shown in the inset of Fig. 1. The low temperature value 2W e is 0.38 (corrected for diffuse elastic scattering [3]) which gives W e ͞W q 2.4, a clear discrepancy compared to the good agreement observed for Ar and Kr. The quantum calculation evidently predicts a

unless certain conditions prevail. The organism must be introduced into the uterus, dead tissue must be present at the time, and the injured tissue must remain in the uterus for long enough to permit incubation. In our patient probably the organism was introduced into the uterus from bowel during the unsuccessful attempt at amiocentesis, because the high vaginal swab taken before the abortion was negative for clostridia. Cl welchii septicaemia, especially when haemolysis is present, is regarded as an indication for total abdominal hysterectomy. The improved survival rates of the early 1970s were attributed to this aggressive surgical approach.2 In the absence of haemolysis, however, prompt and adequate antibiotic treatment with immediate curettage will often effect a cure if coupled with good supportive care.3 We are grateful to Mr M E Pawson and Dr J Curtis for permission to publish this case report. Douglas GW. Toxic effects of Welch bacillus in post abortal infection. NY StateJa Med 1956;56:3673-7. 2 Decker WH, Hall W. Treatment of abortion infected with Clostridium welchii. AmJ Obstet Gynecol 1966;95:394-9. 3Pritchard JA, Whalley PJ. Abortion complicated by Clostridium perfringens infection.